The Ni(II) atom in the title complex, [Ni(C₁₁H₁₃N₃OS)(C₅H₅N)], exists within a square-planar N₃O donor set provided by N,N',O atoms of the dianionic tridentate ligand and a pyridine N atom. The maximum deviation from the ideal geometry is seen in the N-Ni-N five-membered chelate bite angle of 83.28 (12)°. The pyridine mol-ecule forms a dihedral angle of 44.43 (6)° with the N₃O donor set. Supra-molecular stacks along the a axis mediated by alternating π-π inter-actions between the pyridine and five- [centroid-centroid distance = 3.4784 (16) Å] and six-membered [3.4633 (17) Å] chelate rings, feature in the crystal packing.